1. Field of the Invention
The invention relates to an in-sink dishwasher for automatically washing household dishes without requiring the physical space of a built-in automatic dishwasher. In one aspect, the invention relates to a method for controlling the liquid filling operations of the in-sink dishwasher and preventing the normal sink usage from interfering with the dishwasher usage. In another aspect, the invention relates to a drain structure that permits the draining of the liquid while the drain is plugged. In a further aspect the invention relates to the dishwasher having a user interface mounted within the sink and which is covered by the lid when the lid is closed.
2. Description of the Related Art
In-sink dishwashers use the bowl of a sink to form part of the dishwasher housing that defines a wash chamber, with the open top of the bowl providing access thereto. A liquid recirculation system sprays wash liquid throughout the wash chamber to clean any dishes placed within. A lid covers the open top of the bowl when the in-sink dishwasher is being used to prevent the splashing or spraying of the recirculating wash liquid out of the open top of the bowl.
The liquid recirculation system normally operates based on the assumptions that the wash chamber is not filled with liquid and a known volume of liquid is recirculated through the wash chamber. If liquid is present in the wash chamber prior to the initiation of the wash cycle, the liquid can interfere with the direct spraying of liquid on the dishes, reducing the cleaning performance or causing an overflow of the wash chamber.
In the in-sink dishwasher environment, the dual use of the sink as a sink and as the wash chamber for the dishwasher creates the possibility that the user may partially or wholly fill the sink with liquid prior to the initiation of the wash cycle, which can lead to an overfill and possible overflow condition. Alternatively, the user may leave out the sink drain plug which would prevent the retention of the wash liquid within the wash chamber, resulting in the loss of the ability to recirculate the wash liquid. It is highly desirable to have a method for controlling an in-sink dishwasher such that the fill control system monitors for the condition wherein the wash chamber is partially or wholly filled with liquid or the sink drain has not been properly closed.
The use of a plug to close off the drain during the use of the sink during dish washing operations also raises unique problems since most dish washing cycles require the introduction and draining of multiple charges of liquid, yet the sink drain must be closed to permit recirculation of the wash liquid. The sink drain cannot be left open during the dish washing cycles. Thus, the in-sink dishwasher must provide a way to drain the sink while the sink drain is plugged.